Many states (33) now require telemarketers to obtain a state telemarketing license before they can legally call into or out of their state. The licensing processes and requirements vary greatly between states. As part of the licensing process a significant number of states require the telemarketing entity to provide some sort of surety (such as a surety bond, letter of credit, or certificate of deposit) and to pay a registration or licensing fee. Some states even go so far as requiring individual sales agents to register and obtain an individual salesperson license.
Additional information can be found at:
State Telemarketing Registrations